Explain in detail why current transformers cannot operate in open circuit -

There are many kinds of current transformers, and electromagnetic current transformers are used more. This kind of transformer can be divided into measuring current transformer and protective current transformer. Of course, this kind of current transformer cannot be operated in an open circuit. . The structure of the electromagnetic current transformer is somewhat similar to that of a general power transformer. It is also composed of an iron core and a coil. The difference between them is that the primary coil of the current transformer is a large current, high voltage, and the secondary coil is used for measuring instruments or relays with low voltage. The current coils are connected, and the transformer is close to a short circuit state. When the current transformer is running, the secondary circuit must not be open, because when the current transformer is in normal operation, its primary magnetic potential and secondary magnetic potential are in balance, the magnetic potential of the excitation is very small, and the magnetic density in the iron core The induced electromotive force in the secondary coil and the secondary coil is not high. If the secondary coil is open, the primary magnetic potential is all used for excitation, the iron core will be deeply saturated, and the magnetic density will increase to a flat-top state. The open-circuit secondary coil will generate a peak waveform The induced electromotive force with high wave amplitude means that the secondary coil will generate high overvoltage, which will cause great danger to electrical equipment and personal safety. At the same time, after the secondary circuit is opened, the iron core will be seriously saturated, resulting in overheating, and the current transformer will be burned. Therefore, during operation, the secondary circuit of the current transformer is never allowed to open.